Question

HELP ME I WILL GIVE YOU BRAINLIEST

Answer 1

Answer: The mass of the remaining element = 1.1 grams .

Step-by-step explanation:

Exponential equation of decay: $y=A(1-r)^x$ ...(i), where A = intial value , r= rate of decay in decimal , x= time.

As per given :

Initial mass : A= 140 grams

Rate of decay : r= 21.6% per minute= 0.216 per minute.

x= 20  minutes

Substitute values in (i) , we get

$y=140(1-0.216)^20\\\\=140(0.784)^2^0=1.077579422$

Hence, the mass of the remaining element = 1.1 grams .